Camomile (Chamomilla recutita Rauschert (Syn. Matricaria chamomilla (L.)) is used as such or in the form of various preparations. The activity of camomile is attributed to hydrophilic active ingredients such as flavones and polysaccharides and to lipophilic active ingredients which are components of essential camomile oil.
Lipophilic camomile active ingredients that are of importance in assessing the quality of camomile and of camomile extracts are, in addition to (-)-.alpha.-bisabolol and chamazulene, poly-ynes such as cis- and trans-ene-yne-dicycloether (=spiroether). The spiroethers of camomile have anti-inflammatory and spasmolytic properties. These spiroethers are, however, easily decomposed, especially at slightly elevated temperatures.
Cis-ene-yne-dicycloether (also known as cis-spiroether) has the following structure: ##STR1##
Trans-ene-yne-dicycloether (trans-spiroether) has the following structure: ##STR2##
Essential camomile oil can either be obtained by distillation or by extraction of camomile materials, normally dried camomile heads.
Whereas distillation enables an almost complete extraction of the other components of the essential oil, the therapeutically important thermolabile spiroethers are, however, largely decomposed by this process. The oil obtained by distillation consequently no longer displays the active ingredient profile which is characteristic of camomile. On the other hand, it is not possible to obtain the essential oil of camomile completely by extraction. Thus, for example, in the manufacture of fluid extracts with 45% ethanol, only about half of the bisabolol and chamazulene-containing oils contained in the product are recovered in the extract with the sensitive spiroethers.